Device for testing- electric currents



C. F. ARNOLD. DEVECE FOR TESTING ELECTRIC CURRENTS/ APPLICATION FILEDMAR. 21,1918.

Patented Nov. 18, 1919.

ATTOR N EY WITNESSES it 4 mm UNITED STATES PATENT OFFICE.

CARL F. ARNOLD, OF WATSONVILLE, CALIFORNIA.

DEVICE FOR TESTING ELECTRIC CURRENTS.

Application filed March 27, 1918.

To all whom it may concern:

Be it known that I, CARL F. ARNOLD, a citizen of the United States,residing at WVatsonville, in the county of Santa Cruz and State ofCalifornia, have invented cer tain new and useful Improvements in Devices for Testing Electric Currents, of which the following is aspecification.

This invention relates to a new and useful device for testing electriccurrents and the principal object of the invention 1s to provide adevice of this nature which can be used to test the electric system ofan automobile and other internal combustion engines.

Another object of the inventlon is to provide a device of this characterwhereby a' defective spark plug or coil unit can be located in aninstant.

Another object of the invention is to provide a device which can beeasily and readily applied to the part to be tested.

Another object of the invention is to pro vide means whereby the devicecan be held in the hand while the part is being tested or can betemporarily attached to said part.

Another object of the invention is to provide adjustable means on thedevice whereby the strength of the current can be determined.

Another object of the invention is to provide a device of this characterwhich is simple and durable in construction, reliable and eflicient inoperation and one which can be manufactured and placed upon the marketat a minimum cost.

The invention also consists in certain other features of constructionand in the combination and arrangement of the several parts, to behereinafter fully described and specifically pointed out in the appendedclaims.

In describing my inventlon in detail, reference will be had to theaccompanying drawings, wherein like characters denote like orcorresponding parts throughout the several views, and in which:

Figure 1 is a top view of the inventlon.

Fig. 2 is an end view thereof. I

In these figures, 1 indicates the handle of the device made of anysuitable insulating material and I prefer to form this handle of Tshape. Two screws 2 are earned by the head 1 of the handle, one on eachend there- Specification of Letters Patent.

Patented Nov. 18, 1919.

Serial No. 225,010.

of and these screws carry the testing members 3 and 4, said membersbeing of any suitable conducting material and are held on the screws bymeans of the knurled nuts 5 and the posts 6 having the knurled enlargedcentral portions 6. Each member has its outer end forked, as at 7 andextended beyond the opposite sides of the handle to engage with thespark plug and the member 3 has its inner end turned up, as at 8, andthe other member 4 is of considerably greater length than the member 3and is bent upwardly and inwardly so that the end lies directly over thebent-up end 8 of the member 3. The extreme end is then bent over to forma loop 4 and both portions of the loop are formed with a screw threadedhole therein to receive a screw 9, the point of said screw beingdirectly over the turned-up end 8 so that when a spark plug is to betested the current is caused to jump the gap between the screw and theturned-up end 8 to complete the cir cuit. The loop A prevents movementof the screw, due to vibrations or the like, as it has the effect of aspring and thus holds the screw firmly against movement. By adjustingthe screw in relation to the turned-up end 8 the strength of the currentis determined.

It is thought from the foregoing that the advantages and novel featuresof my invention will be readily apparent.

I desire it to be understood that I may make slight changes in theconstruction and in the combination and arrangement of the severalparts, provided that such changes fall within the scope of the appendedclaims.

I claim as my invention:

1. A device for testing electric currents comprising a handle part ofinsulating material, a pair of conducting members on said handle havingtheir adjacent ends spaced apart, one member having a spring loop formedthereon and a screw member passing through said spring loop.

2. A device for testing electric currents comprising a handle part ofinsulating material, a pair of conducting members secured to one facethereof and having their outer ends extending beyond the opposite sidesof the handle, the inner terminal of one of said members being bentupwardly of the face of the handle to which it is secured, the innerterminal end of the other member being bent In testimony whereof I affixmy signature inwafdly to be arrangei above the tegminal in presence oftwo Witnesses.

of t 1e co-acting con uct'm mem er in T spaced relation to form a sgarkgap, and CARL ARA means on one conducting member to regulate \Vitnesses:

the space between the terminals of the con- A. S. CHRISTENSEN,

ducting members. C. R. TAYLOR.

